EP3682131B1 - Overrunning clutch - Google Patents

Description

The invention relates to a self-shifting overrunning clutch which is set up for use in a drive train of a motor vehicle, in particular in a passenger vehicle. The invention also relates to the use of such an overrunning clutch in an axle drive unit, preferably driven by an electric motor, for driving the wheels of an axle of a motor vehicle, in particular a car, as well as an axle drive unit equipped with such an overrunning clutch.

Freewheel clutches which enable two coupling members to rotate freely relative to one another in a free-wheeling direction of rotation and which produce a rotationally fixed connection between the two coupling members in a direction of rotation opposite to the free-wheeling direction (load direction of rotation) are known to those skilled in the art. Overrunning clutches can be used as overrunning clutches or as backstops.

Overrunning clutches with spring-loaded pawls are common, which are pivotably arranged on one of the two coupling members or on an intermediate member arranged between the two coupling members and ensure free rotation or a non-rotatable connection between the coupling members depending on the direction of relative rotation of the coupling members to one another. The typically permanently spring-loaded pawls come into contact with driving stops in a form-fitting manner in order to produce a non-rotatable connection in the rotational stress or load rotational direction opposite to the freewheeling direction. When the overrunning clutch is stressed in In the free-running direction of rotation, however, the pawls sweep over the driving stops without blocking a rotation of the coupling members relative to one another.

A disadvantage of such overrunning clutches is that the torque to be transmitted via the clutch in the load rotation direction is to be transmitted via the pawls and the driving stops. As components to be designed relatively filigree, the pawls, which are pivotable and spring-loaded within the clutch via even more filigree components, have only a low torque transmission potential. This is all the more true when the effective diameter on which the pawl acts on the coupling members are small and a torque to be transmitted has to be supported by a small lever arm and, due to the small diameter, fewer or only relatively small pawls are distributed over the circumference can. In addition, the sweeping over of the driving stops by the pawls permanently engaged against them causes a noise typical of many overrunning clutches, which becomes increasingly louder with increasingly larger and more stable clutches and can be unacceptably annoying.

Against this background, overrunning clutches have been developed in which an intermediate member acting between the two coupling members of the overrunning clutch is used, which is displaceable in the axial direction between a freewheeling position and an engagement position in which the intermediate member is in engagement with the two coupling members via a highly resilient load toothing is.

From the pamphlet DE 763 479 An overrunning clutch is known in which a clutch claw member arranged between a first clutch member and a second clutch member is axially displaced from a freewheeling position into an engagement position in order to positively couple the two clutch members to one another in at least one rotational load direction via a toothing pointing in the axial direction. Furthermore, a locking mechanism is provided in which the one-way clutch can be locked as a whole via the axial displacement of a sliding ring, so that it generates torque in both Able to transmit directions. An overrunning clutch with similar functionality is in the document DE 2 354 332 disclosed, with teeth pointing radially inwards and outwards being provided here.

The pamphlet EP1 148 264 discloses an overrunning clutch for a bicycle.

Such overrunning clutches are complex and expensive to manufacture. They are particularly large in the axial direction and provide control pawls which, when the clutch is in the freewheeling position, are permanently spring-loaded against control stops or sweep over them, so that when such a freewheel clutch is used, audible noise is to be expected. Due to the complex structure of the intermediate link, the masses to be moved are large and the switching pulses that occur during a switching process are high.

For applications in motor vehicle construction, in particular for applications in a part of a drive train, which require a high torque transmission potential due to the provision of reduction stages and for which a particularly compact, space-saving overrunning clutch that can be integrated into the surrounding drive train architecture, is easy to manufacture and is less prone to failure is desirable , which switches quickly and with small masses to be moved and small mechanical switching pulses and is intended to provide a noiseless freewheel, such freewheel clutches are therefore not suitable and do not represent a sensible application for a specialist in automotive drive technology.

It is therefore the object of the invention to provide an overrunning clutch that is particularly suitable for use in a drive train of a motor vehicle, in particular in a preferably electric motor-driven axle drive unit, which is easy to integrate and less prone to failure and which is capable of transmitting a high torque and has a compact design , is easy to manufacture and works largely noiselessly even in the freewheeling direction of rotation. The masses to be moved for a switching process should be kept small so that only small switching impulses occur during a switching process and these are carried out quickly can. It is also an object of the invention to provide an axle drive unit with such an overrunning clutch.

The overrunning clutch according to the invention is formed by an overrunning clutch with a first coupling member, a second coupling member and an intermediate member interacting with the first coupling member and the second coupling member, which, depending on the direction of the rotational stress on the overrunning clutch, has a freewheeling position in which one coupling member can rotate freely with respect to the other in a freewheeling direction of rotation is enabled, or an engagement position in which via the intermediate member a non-rotatable connection between the two coupling members is established in a rotational stress opposite to the freewheeling direction of rotation or in a load direction of rotation, wherein the intermediate member is axially displaceable and a change between the freewheeling position and the engagement position takes place by an axial displacement of the intermediate member, and wherein at least one control mechanism is provided which the axial displacement of the intermediate member from de r free-running position into the engaged position via a control element, in particular by means of a control pawl, initiated.

In a first advantageous embodiment of the invention it is provided that the first coupling member axially overlaps the second coupling member in the engaged position to form an effective tooth width and the control element, in particular the control pawl, is at least partially, but in particular completely, arranged within the tooth width on the intermediate member.

In addition or as an alternative to the above-mentioned advantageous embodiment, it can be provided that the control element is arranged on the intermediate member and, in the freewheeling position, comes into contact with a load toothing provided on the first coupling member or on the second coupling member in order to initiate the axial displacement of the intermediate member into the engagement position when the torsional stress changes from the freewheeling direction of rotation to the direction of load rotation.

Both configurations described above can contribute both together and as alternatives to realizing an overrunning clutch in the desired advantageous manner. However, it is particularly preferred if both configurations are used together.

The gearing width B is the width of the overall gearing overlap that is effective for the torque transmission in the engaged position and is defined by the axial distance that the load gear pairs effective for the torque transmission between the intermediate member and the first coupling member and between the intermediate member and the second coupling member in the engaged position span as a whole. The toothing width is thus defined by the distance B between two outer load toothing planes which are perpendicular to the axis of rotation and in which, in the engagement position, one load tooth pairing is still in effective engagement. Both load gear planes can be defined by the same load gear pair or a first load gear plane can be defined by a first load gear pair and a second load gear plane can be defined by a second load gear pair.

A load tooth pairing is the pair of teeth between the first coupling member and intermediate member as well as the tooth pairing effective between the second coupling member and the intermediate member, via which torque is transmitted from the first coupling member to the second coupling member or vice versa when the clutch is stressed against the freewheeling direction (load rotation direction) with the interposition of the intermediate member.

In the case of a freewheel clutch configured in this way, it can preferably be provided that the intermediate member and more preferably also the control mechanism is arranged at least partially, but advantageously completely, within the toothing width generated. The intermediate member and also the control mechanism are preferably arranged completely within the toothing width, at least in the engagement position.

The above-described arrangement of the control element enables a compact design which also has a very high torque transmission potential with a corresponding configuration of the engagement that ensures the positive fit between the coupling members and the intermediate member.

The intermediate member can be ring-shaped and have an outer ring surface at least partially provided with an outer load toothing and an inner ring surface at least partially provided with an inner load toothing, the outer load toothing and the inner load toothing at least partially overlapping one another viewed in the radial direction. In particular, the outer load toothing can at least partially, preferably completely, cover the inner load toothing. The outer ring surface is preferably provided with a circumferential outer load toothing over the full axial width of the intermediate member, while the inner ring surface is provided with a circumferential inner load toothing only in an axial section.

The load gears provided on the intermediate member cooperate in a load-transmitting manner with corresponding load gears on the coupling members in the engaged position. With load gearing is meant the gearing provided on a coupling member or on the intermediate member, by means of which a load-transmitting form fit is established between the individual components when the intermediate member is in the engagement position. The design of the intermediate member as an intermediate ring with load gears provided on the inner and outer ring surfaces on the radially inside and radially outside enables the desired high torque transmission potential of the overrunning clutch.

In order to enable the axial displacement, it can be provided that the intermediate member has a helical toothing on the radially inwardly facing annular surface or on the radially outwardly facing annular surface, the helical toothing on the intermediate member having a corresponding helical toothing is in load-transferring engagement on one of the coupling members in the event of torsional stress counter to the freewheeling direction. The helical toothing exerts an axial force on the intermediate member, by means of which - depending on the direction of loading - it is forced out of the engaged position into the free-running position or from the free-running position into the engaged position. The helical toothing thus not only has a load-transferring function as a load toothing, but also a control function and thus also forms a control toothing at the same time. The intermediate member is preferably in load-transmitting engagement over the entire axial length of the helical toothing provided on the intermediate member with the helical toothing provided on one of the coupling members when the overrunning clutch is rotationally stressed against the freewheeling direction of rotation and the intermediate member is in the engaged position. The helical toothing can extend over the entire axial length of the intermediate element or only be provided in sections in an axial partial area. It is preferably provided that the load toothing provided on the outer ring surface of the intermediate member is formed by a screw toothing.

Depending on the structural design of the coupling, the intermediate member can be located completely inside the overlap, both in the engaged position and in the free-wheeling position, with which the first coupling member engages over the second coupling member to form an axial overlap area or annular space between the first and second coupling members in the engaged position . The intermediate member can also only be in the free-wheeling position or only in the engaged position completely in the overlap area or the annular space, while in the other position it is at least partially out of the space radially inside of the overlap or the area due to the axial displacement causing the position change by the overlap generated annular space protrudes between the first and second coupling member.

In an advantageous embodiment, the control mechanism comprises a control element, preferably in the form of a control pawl, which is freely pivotably mounted or freely pivotably supported on the intermediate member. With "freely pivotable" is a bearing or a support is meant in which the control pawl is not pretensioned against control stops in a certain pivoting direction by an adjusting means such as a spring. Due to the arrangement of the control pawl on the intermediate member, the first coupling member and the second coupling member can also be made structurally simpler and the integration of the control pawl into the intermediate member contributes overall to the compactness of the overrunning clutch. The control element or the control pawl is also designed exclusively to initiate the axial displacement of the intermediate member. The control pawl also does not perform a load-transmitting function in the engagement position, in which the control pawl is preferably kept completely free of load, or at least not to a significant extent.

Because the at least one control pawl is arranged on the intermediate member, a particularly compact design of the overrunning clutch that can nevertheless be loaded with high torque can be implemented. In particular, the control pawl can be pivotably mounted on the intermediate member in such a way that the control pawl is located completely and preferably axially within the outer toothing planes defining the toothing width both in the engagement position and in the free-running position. However, embodiments are also conceivable in which the control pawl is only partially located in the free-wheeling position and / or in the engaged position within the planes defining the toothing width.

The control mechanism is set up in such a way that it enables the axial displacement of the intermediate member from the free-wheeling position into the engaged position only in defined angular positions ensuring the transition of the intermediate member into the engaged position. The control pawl, which forms part of the control mechanism, is therefore also a synchronization pawl, through which the transition of the intermediate member from the free-running position to the engaged position can only take place if the alignments of the load gears producing the positive fit between the intermediate member and the coupling member in the engaged position are in a rotational angle position to one another which enables the transition of the intermediate member from the free-wheeling position to the engaged position.

In order to actuate the control and synchronization pawl or the control element, the control mechanism can comprise a control part which, depending on the direction of rotation of a relative rotation between the coupling members, urges the control pawl from an open position into an engaged position or from an engaged position into an open position. The engagement position is the position in which the control pawl comes into contact with a control stop, as a result of which the intermediate member is urged into the engaged position in cooperation with one of the coupling members. The open position is a position in which the control pawl is in particular when the clutch is stressed in the freewheeling direction of rotation.

It has proven to be particularly advantageous if the control part interacts with a coupling member in such a way that it continuously pushes the control element, which is preferably designed as a control pawl, into the open position and is able to hold it there permanently when the overrunning clutch is stressed in the freewheeling direction of rotation. Such a configuration has the particular advantage that the control pawl does not strike against an area of a coupling member providing the control stops and the coupling therefore behaves with little noise even when it is stressed in the freewheeling direction.

In order to enable the desired low-noise behavior, it is provided that the control part is in frictional contact with a coupling member and, when the coupling members rotate relative to one another, is directly or indirectly positioned against the control pawl, subject to frictional force. This can be ensured that the control pawl engages in the control part and so the control pawl interacts directly with the control part. However, an embodiment is preferred in which a control arm interacting with the control pawl engages in the control part. Here, the control part only interacts indirectly with the control pawl, in that the control part exerts an actuating force on the control arm exerts, which transmits this to the control pawl as an actuating torque by means of which the control pawl is pushed from the engaged position into the open position or from the open position into the engaged position.

The control arm and the control pawl can advantageously be axially offset from one another so that the control part, control pawl, control arm and control stops can be arranged in a structurally simple manner with an axial offset to one another within the toothing width and can interact with one another.

A configuration in which the control part is designed as a one-part or multi-part friction ring that is in frictional contact with a coupling member is regarded as particularly advantageous. Such a friction ring interacts with the control pawl directly or indirectly in the manner described above and can in particular form a projection or several projections with which the control element, in particular the control arm or the control pawl, comes into contact with the exertion of an actuating force. The friction ring can be in frictional contact with a radial friction surface (a friction surface pointing radially outward or radially inward) and / or within an annular groove with side surfaces by which the annular groove is axially delimited.

To receive the control pawl, control element receptacles, in particular control pawl receptacles, can be made in the intermediate member in the form of radial pocket-like depressions or openings. In order to keep the intermediate member sufficiently resilient in the area of such control element receptacles despite the material recesses required for this, it can be provided that in the area of these control element receptacles the radially inner and / or the radially outer load toothing on the intermediate element is dispensed with by creating a toothing interruption, i.e. none "Tooth gaps" of the load gearing are provided in the area of the control pawl mount. The load toothing on one of the coupling members that interacts with this on the intermediate member is the configuration of the load toothing configured on the intermediate ring trained accordingly. A plurality of control element receptacles are preferably arranged on the intermediate member, which can advantageously be distributed evenly over the circumference of the intermediate member. An embodiment is preferred in which two control element receptacles are formed diametrically opposite one another on the intermediate member, preferably each in the area of a toothing interruption.

In order to initiate the change of the intermediate member from the free-wheeling position into the engaged position, it can be provided that the control pawl, in an engaged position, comes into contact with control stops provided on a coupling member. The embodiment described at the outset, in which the control stops are formed by parts of a load toothing provided on a coupling member, is particularly advantageous.

In a particularly preferred embodiment, the overrunning clutch can also be designed as a lockable overrunning clutch, in which a locking member is provided that blocks the axial displacement of the intermediate member from the engaged position into the freewheeling position when the locking member is in a blocking position, and the axial displacement of the Releases the intermediate member from the engaged position into the free-running position when the locking member is in a release position.

A structurally easy to implement design and integration of a locking element provides that the locking element has a locking toothing corresponding to the screw toothing provided on one of the coupling members or a locking toothing corresponding to the load toothing of a coupling member, which is connected to the screw toothing or load toothing provided on the respective coupling member, which the Locking toothing corresponds to being in overlap when the locking member is in the release position, so that the intermediate member can move axially into the locking member to assume the free-wheeling position. When the locking element is in the blocking position, however, the locking toothing is rotated with respect to the screw toothing or load toothing, so that the intermediate element cannot leave the engagement position because it is pushed against the locking teeth and thus blocked by them. The individual teeth of the locking teeth form individual locking elements.

The locking member is preferably an externally or internally toothed locking ring which is rotated for the change between the blocking position and the release position.

The blocking element can also be designed as an externally switchable blocking element which can be transferred from the blocking position into the release position and / or from the release position into the blocking position by an external actuation. One of the two positions of the locking element or the actuator system which actuates the locking element can be designed as a basic position which the locking element or the actuator system assumes automatically when it is not subjected to force by the actuator system ("normally blocked" or "normally free"). For the automatic return to the basic position, a return means, for example a return spring, can provide a return force.

As an alternative to such a monostable design, a bistable design can also be selected in which the locking member independently and permanently maintains the switching position (blocking position or release position) once it has been taken into this position.

For the actuation of the locking member, various fundamentally known operating principles come into consideration, such as hydraulic, pneumatic or electromagnetic actuation. Ramp or cam mechanisms can also be used.

The locking member can also be designed as a self-switching locking member, in which at least one locking element or a plurality of locking elements are thereby pushed from a blocking position into a release position or from a release position into a blocking position, that within the clutch, depending on the operating state, and on the locking member or . on forces acting on the locking member actuation are used as actuating forces for adjusting the locking member and the locking elements. For example, centrifugal forces can be used as actuating forces to force the locking member out of a blocking position into a release position or from a release position into a blocking position as a result of exceeding a certain limit speed.

An advantageous application of a freewheel clutch according to the invention is, in particular, its use in an axle drive unit for a drive train of a motor vehicle. Such a use comes into consideration in particular with an electromotive axle drive unit in which a 2-speed planetary gear unit, in particular a multi-stage 2-speed planetary gear, provides various gear ratios between an electromotive drive motor and the drive wheels of an axle and, if necessary, the recuperation mode and / or a reverse gear. With regard to the at least also and preferably purely electric motor-operated axle drive unit with an overrunning clutch and the use of the overrunning clutch in such an axle drive unit, reference is made to the international patent application PCT / EP2016 / 079169 , in which the use of an overrunning clutch in an axle drive unit and the axle drive unit itself is described and the content of which, in particular if this relates to the function and use of the overrunning clutch and the arrangement of an overrunning clutch on an axle drive unit, is hereby incorporated into this application.

Figur 1

eine als Rücklaufsperre eingesetzte sperrbare Freilaufkupplung in einer Außenansicht mit einem als Kupplungsglied fungierenden Kupplungsgehäuse,

Figur 2

die Freilaufkupplung gemäß den vorherigen Figuren unter Weglassung des Kupplungsgehäuses mit einem in Eingriffsstellung befindlichen Zwischenglied und einem in Blockierstellung befindlichen Sperrglied,

Figur 3a

die Freilaufkupplung gemäß den vorherigen Figuren in einer Schnittansicht in der auch in Figur 2 gezeigten Eingriffsstellung,

Figur 3b

die Freilaufkupplung aus gemäß den vorherigen Figuren in einer Schnittansicht mit einem in Freilaufstellung befindlichen Zwischenglied und einem in Freigabestellung befindlichen Sperrglied,

Figur 4a

die Freilaufkupplung gemäß den vorherigen Figuren in einer Draufsicht in der auch in Figur 2 und Figur 3a gezeigten Eingriffsstellung,

Figur 4b

die Freilaufkupplung gemäß den vorherigen Figuren in einer Draufsicht in der auch in Figur 3b gezeigten Freilaufstellung unter Weglassung eines vorderen Teils des Zwischengliedes,

Figur 4c

die Freilaufkupplung gemäß den vorherigen Figuren in einer Draufsicht in der auch in Figur 2 und Figur 3a gezeigten Eingriffsstellung unter Weglassung des Sperrglieds und eines vorderen Teils eines inneren Kupplungsglieds,

Figur 5a

die Freilaufkupplung gemäß einer der vorherigen Figuren in einer perspektivischen Ansicht in der auch in Figur 2 und Figur 3a gezeigten Eingriffsstellung von hinten unter Weglassung des Kupplungsgehäuses, des Sperrglieds und des Zwischenglieds,

Figur 5b

die Freilaufkupplung gemäß einer der vorherigen Figuren in einer perspektivischen Ansicht in der auch in Figur 3b gezeigten Freilaufstellung von hinten unter Weglassung des Kupplungsgehäuses, des Sperrglieds und des Zwischenglieds,

Figur 5c

die Freilaufkupplung gemäß einer der vorherigen Figuren in einer perspektivischen Ansicht in einer Zuschaltposition,

Figur 6a

ein bei den Freilaufkupplungen gemäß einer der vorherigen Figuren eingesetztes Steuerteil in Form eines Reibrings,

Figur 6b

das Steuerteil aus Figur 6a in einer Explosionsdarstellung,

Figur 7a

eine alternative Ausgestaltung eines als Reibring ausgebildeten Steuerteils in einer perspektivischen Ansicht, und

Figur 7b

den in Figur 7a gezeigten Reibring in einer Seitenansicht.

In the drawings shows

Figure 1

a lockable overrunning clutch used as a backstop in an external view with a clutch housing functioning as a clutch member,

Figure 2

the overrunning clutch according to the previous figures omitting the clutch housing with one in the engaged position Intermediate member and a locking member in the blocking position,

Figure 3a

the overrunning clutch according to the previous figures in a sectional view in the also in Figure 2 engagement position shown,

Figure 3b

the overrunning clutch from according to the previous figures in a sectional view with an intermediate member in the freewheeling position and a locking member in the release position,

Figure 4a

the overrunning clutch according to the previous figures in a plan view in the also in Figure 2 and Figure 3a engagement position shown,

Figure 4b

the overrunning clutch according to the previous figures in a plan view in the also in Figure 3b shown free-wheeling position with omission of a front part of the intermediate link,

Figure 4c

the overrunning clutch according to the previous figures in a plan view in the also in Figure 2 and Figure 3a engagement position shown omitting the locking member and a front part of an inner coupling member,

Figure 5a

the overrunning clutch according to one of the previous figures in a perspective view in the also in Figure 2 and Figure 3a engagement position shown from behind, omitting the clutch housing, the locking member and the intermediate member,

Figure 5b

the overrunning clutch according to one of the previous figures in a perspective view in the also in Figure 3b shown free-wheeling position from behind omitting the clutch housing, the locking member and the intermediate member,

Figure 5c

the overrunning clutch according to one of the previous figures in a perspective view in an engagement position,

Figure 6a

a control part in the form of a friction ring used in the one-way clutches according to one of the previous figures,

Figure 6b

the control unit off Figure 6a in an exploded view,

Figure 7a

an alternative embodiment of a control part designed as a friction ring in a perspective view, and

Figure 7b

the in Figure 7a shown friction ring in a side view.

Figure 1 shows a lockable overrunning clutch used for illustration purposes in an external view. The overrunning clutch can, for example, be fixed to an axle drive unit of a motor vehicle via the housing and used as a backstop, via which a sun, a planetary gear set or a ring gear of a 2-speed planetary gear can be blocked in one direction of rotation and another can be released in another direction of rotation. The housing functions as a first coupling element 1, which - depending on whether the overrunning clutch is in a freewheeling position released by a locking element or in an engaged position - allows the rotation of a second coupling element in a freewheeling direction or if there is a torsional stress opposite to the freewheeling direction ( Direction of rotation of the load).

In the exemplary embodiment shown in the figures, the first coupling member 1 is an outer, standing coupling member, by means of which a reverse rotation of a second coupling member 2 in a direction of rotation opposite to a freewheeling direction can be prevented. However, with a different configuration of the overrunning clutch, the first coupling member can also be a rotatably mounted coupling member and / or an inner coupling member while maintaining the functions of the overrunning clutch described below. Use of a clutch designed according to the exemplary embodiments as an overrunning clutch is therefore also conceivable.

Figure 2 grants a view of the inner workings of the in Figure 1 one-way clutch shown.

In the Figure 2 The illustrated position of the overrunning clutch is an engagement position. Between the outer, first coupling member 1 (corresponds to the coupling housing in Figure 1 , in Figure 2 omitted) and an inner, second coupling member 2, an axially displaceable intermediate member 3 is arranged. The intermediate member 3 is as formed externally and internally toothed ring and received in an annular space between the outer, first coupling member and the inner, second coupling member 2, which is created by the fact that the first coupling member engages over the second coupling member in the axial direction. In the exemplary embodiment shown in the figures, the first coupling member is the outer coupling member which axially overlaps the inner, second coupling member 2.

The intermediate member 3 has a helical toothing 4 'as the outer load toothing and an internal toothing 5' as the inner load toothing. The outer helical toothing 4 'protrudes from one provided on the inner side of the outer coupling member 1, in particular also from Figure 3b and Figure 4c visible inner helical toothing 4 "over the entire length of the outer helical toothing 4 '. The outer helical toothing 4' extends in the embodiment illustrated by the figures over the entire axial width of the intermediate member 3. Other embodiments in which the screw toothing is shorter and extending only over one or more axial sections of the intermediate member are also conceivable Figure 2 , Figure 3a and Figure 4a The engagement position shown in engagement with an external toothing 5 "provided on the second coupling member 2. The internal toothing 5 'on the intermediate member 3 and the external toothing 5" on the inner, second coupling member 2, when viewed in the axial direction, extend only over a short axial portion of the intermediate member 3 or of the inner coupling member 2 and are only in load-transmitting engagement with one another in the engagement position.

The gear engagement pairings 4 '/ 4 "and 5' / 5" described form the load gear pairings via which torque is transmitted between the coupling members 1, 2 with the interposition of the intermediate member when the overrunning clutch is used as intended. These load gear pairings are distributed axially in the engagement position over a gear width B, which consists of Figure 3a can be seen. The toothing width B is defined by the axial distance from the outer toothing planes perpendicular to the axis of rotation, in which on the inside and / or outside of the intermediate link effective load gear pairings are just still effective.

Since in the embodiment shown in the figures, a load toothing 4 'arranged on the intermediate member and in engagement with the first coupling member 1 extends over the entire width of the intermediate member 3 and the load toothing 5' engaging with the second coupling member 2 does not axially overlap the load gearing 4 ′ extends out, the gearing width B corresponds at the same time to the axial width of the intermediate member 3.

The intermediate member 3 is arranged axially displaceably between the inner coupling member 2 and the outer coupling member 1 and, under the action of the helical gear pairing 4 '/ 4 ", can be extracted from the in Figure 2 and Figure 3a engagement position shown axially in the in Figure 3b shown free-wheeling position are shifted. While in Figure 3a the intermediate member 3 and the inner coupling member 2 are engaged in an engagement position for load transmission via the gear pairing 5 '/ 5 "and the intermediate member 3 is supported with its axially outer surface pointing to the right against the roller bearing 31, the intermediate member 3 is in the in Figure 3b position shown shifted to the left while disengaging from the inner coupling member 2.

For this purpose, a locking ring 6 functioning as a locking member was initially used from the in Figure 2 and Figure 3a blocking position shown, which is also shown in Figure 4a is shown in the in Figure 3b and Figure 4b Released position shown rotated relative to the first coupling member 1. In the in Figure 2 , Figure 3a and Figure 4a The blocking position shown is blocked by a toothing on the locking ring 6, which corresponds to the screw toothing 4 ″ provided on the inside of the outer coupling member 1, as locking toothing 7, initially blocks an axial displacement of the intermediate member 3 to the left 6 associated locking member actuators 8, the locking ring is in the in Figure 3b and Figure 4b The release position shown is rotated, in which the locking toothing 7 is provided with the one provided on the inside of the outer coupling member 1 The screw toothing 4 ″ overlaps so that the intermediate member 3 can move into the locking toothing 7. Then the intermediate member 3 and the inner coupling member 2 disengage and the inner, first coupling member 2 can freely move into the in Figure 4b Rotate indicated freewheeling direction of rotation F.

The provision of a locking member is not absolutely necessary for the function of the clutch as a mere overrunning clutch, which allows free rotation in a freewheeling direction and a load transfer when a rotational stress is opposite to the freewheeling direction. However, it offers the possibility of blocking the clutch in the engaged position and thus, when the blocking element is in the blocking position, also to enable load transfer in the freewheeling direction of rotation, in that the blocking element prevents the intermediate element from being able to assume the freewheeling position.

In the Figures 2 to 5b it can be seen that two control pawls 9, which also function as synchronization pawls, on the intermediate member 3 within the toothing width B and radially on the inside of the overlap, in which the outer, first coupling member 1 and the inner, second coupling member 2 overlap to form an annular space overlaps, are arranged. The control pawls 9 are arranged in two diametrically opposite pocket-like openings in the intermediate member 3 ( Figure 2 and Figure 4c ) and received in the intermediate member 3 such that they can pivot freely and are supported radially on the outside with their side facing away from the intermediate member against the first coupling member 1. An additional storage element interacting with the control pawls is not provided. Instead of such a free inclusion of the control elements in the intermediate member and its support on the adjacent coupling member, which ensures that the control elements can support a high load, it is also possible that the control pawls 9 on bearing pins that are supported on the side of the control pawls on the intermediate member and engage in the control pawl, are pivotably mounted.

The number of two control pawls shown in the figures and their diametrically opposite arrangement, which advantageously loads the intermediate ring symmetrically in the circumferential direction, has proven to be an advantageous embodiment. However, a different number of control pawls can also be provided (one or more than two) and a different arrangement can be selected.

the end Figure 3a, Figure 3b , Figure 4c, Figure 5a, Figure 5b and Figure 5c it can be seen that the control pawls 9 are in engagement with a control member designed as a friction ring 12 via a control arm 11 offset axially relative to the control pawls 9. The friction ring 12 is in frictional contact with the inner coupling member 2 and with the inner ring of the bearing 31, but when the inner coupling member 2 and intermediate ring 3 rotate relative to each other, the control arm 11 is connected to the intermediate member 3 on the one hand and to the friction ring 12 on the other cooperates positively, prevented from rotating with the inner coupling member 2 and the inner ring of the bearing 30 that rotates with it. Rather, the friction ring 12 with the projections formed thereon, which are formed by recesses 13 in the friction ring 12, is pushed against the control arms 11, which thereby experience an actuating force acting in the circumferential direction of the friction ring 12, which in turn exerts an actuating torque on the control pawls 9 . Depending on the relative direction of rotation between the inner coupling member 2 and the intermediate member 3, the control pawls 9 are either pushed into an open position in which the free ends of the control pawls 9 are pivoted away from the first coupling member 2 in the radial direction and are beyond the reach of the inner coupling member 2 provided external toothing 5 ". Or the control pawls 9 are pushed into an engagement position in which the free ends of the control pawls 9 are urged radially inward in the direction of the first coupling member 2 and thereby come into contact with the external toothing 5". With a relative rotation of the inner coupling member 2 with respect to the intermediate ring 3 in the freewheeling direction of rotation F ( Figure 4b, Figure 5b ) the control pawls 9 are thus permanently pushed outwardly out of engagement with the toothing 5 ″ provided on the inner coupling member 2 into the open position. In the event of a relative rotation of the inner coupling member 2 with respect to the intermediate ring 3 in the load rotation direction M ( Figure 4c and Figure 5a ) the control pawls 9 are pivoted inwardly into the toothing 5 ″ provided on the inner coupling member 2 and assume an engagement position.

The projections formed on the friction ring 12, which in the embodiment shown are formed by the edges of the recesses 13 pointing in the circumferential direction, have an effective width that enables an axial displacement of the control pawl or control arm resting against it, which extends in the axial direction with the intermediate member 3 move along.

The above-described interaction of the control pawls with a control member that actuates the control pawls depending on the relative direction of rotation between the intermediate member and a coupling member has the advantage that the control pawls behave noiselessly, unlike control pawls that are permanently employed against control stops via a spring element. In addition, the toothing used as a load toothing on a coupling element is also used as a control stop, which represents a significant structural simplification, since this eliminates the need for the control toothing that is otherwise to be provided in addition to a load toothing and forming control stops.

The following describes the processes involved in changing the direction of loading.

If the overrunning clutch is in the in Figure 3a engagement position shown and the inner coupling member 2 is acted upon by force in the load direction of rotation M, the torque is transmitted from the inner coupling member 2 to the intermediate ring. This is in engagement with the outer coupling member 1 via the screw tooth pairing 4 '/ 4 "and is in Figure 3a pushed to the right against the inner ring of the bearing 31 and over this is supported on the assembly with which the outer coupling member 1, which is formed by the coupling housing, is firmly connected. In the loading direction M, the inner coupling member 2 is accordingly in a rotationally fixed, form-fitting connection with the outer coupling member 1 via the intermediate member. Due to the design of the form fit by means of highly resilient load gears, the clutch has a very high torque transmission potential despite its compactness.

Now finds a change in the direction of loading to the in Figure 3b instead of freewheeling direction F, the intermediate member 3 initially pushes to the left as a result of the screw tooth pairing 4 '/ 4 "which is now acted upon in the load direction F. Due to the locking ring 6 in the blocking position, the locking tooth 7 of which blocks the gears of the screw tooth 4" is a Movement of the intermediate member such that it disengages from the inner coupling member is excluded. The freewheel is blocked in this way and the clutch can function as a fixed clutch and also transmit torque in the freewheeling direction F.

If the locking ring 6 is rotated via the locking element actuators 8 in the case of a loading direction in the freewheeling direction F or before a change in the loading direction in the freewheeling direction F, in order to bring the locking toothing 7 into overlap with the inside screw toothing 4 ″ and thus into the release position the intermediate member 3 pushing to the left through the helical gear pairing 4 '/ 4 "move into the locking ring 6 until the gear pair 5' / 5" disengages between the intermediate member 3 and the inner coupling member 2. The inner coupling member 2 can now rotate freely in the freewheeling direction. The in Figure 3b The state shown has been reached.

In this state, the inner clutch 2 also urges the friction ring 12 in the freewheeling direction F due to the friction force Via the entrainment projection formed by a control edge 10 of the recess 13, which is in contact with the control arms 11, an actuating force is exerted on the control arms 11 and thus an actuating torque initiated by friction on the control pawl 9 and in this way continuously pushes it into the open position ( Figure 4b, Figure 5b ).

When the load direction changes again from the freewheeling direction F to the opposite load direction (load rotation direction M), the inner coupling member 2 initially rotates a small angular amount in the direction of rotation M, which results in a change in the effective direction of the actuating force between the friction ring 12 and the control arm 11 . The actuating force now exerted on the control arm 11 via a control edge 10 of the friction ring 12 causes, at least for a short time, a friction force-initiated actuating torque acting on the control pawls 9, as a result of which the free ends of the control pawls 9 pivot inward into an engagement position and with the outer load toothing 5 ″ on the inside Coupling link 2 come into contact ( Figure 4c , Load gearing 5 "outside the drawing plane or Figure 5c , in which the intermediate ring is not yet in the engaged position). Via the control pawls 9, an outgoing torque from the inner coupling member is now exerted on the intermediate member 3, as a result of which the intermediate member 3 is urged back to the right into the engagement position under the action of the helical gear pairing 4 '/ 4 "until it is again the in Figure 3a shown and in Figure 5a has assumed engagement position which can be derived from the position of the control pawls, in which a torque to be transmitted is transmitted via the highly stressable gear pairings 4 '/ 4 "and 5' / 5". The control pawls 9 are virtually load-free in the engaged position.

In order to enable the movement into the engagement position, the geometrical dimensions and the positioning of the control pawls 9 on the intermediate link are matched to the gear pairing 5 ', 5 "or synchronized with them, that when the control pawls 9 with the gear 5" come into contact with the coupling member 2, the toothing 5 'provided on the intermediate member can move laterally into the toothing 5 "provided on the coupling member 2 (Tooth in tooth gap). The control pawls 9 and the load gearing 5 ″ thus also have a synchronization function.

The control part designed as a friction ring 12 is shown in detail for illustrative purposes Figure 6a and Figure 6b shown in a relaxed position.

The friction ring 12 has a number corresponding to the number of control pawls or control arms and recesses 13 that are positioned accordingly on the intermediate member and into which the control arms 11 cooperating with the control pawls 9 can engage and are formed by the control edges 10 that are connected to the control arm 11 come into contact in order to be able to transmit the actuating forces exerted by the friction ring to the control arm 11. Of course, different types of projections or other means that enable the friction ring 12 to come into contact with the control arm 11 or directly against a control pawl 9 can also be provided.

On the multi-part friction ring 12, friction members 14 which act in the axial direction and extend over at least a partial section of the circumference are provided, which are assigned to a carrier ring 15. Friction members 14 and carrier ring 15 engage with one another via corresponding locking means 16 'and 16 "in such a way that the friction members are at least to a small extent axially displaceable with respect to carrier ring 15, but nonetheless secured against rotation with respect to carrier ring 15. In carrier ring 15 are receptacles for Pre-tensioning elements 17, preferably in the form of the spiral springs shown in the figures, are provided, by means of which the friction members 14 are urged away from the carrier ring 15 in the axial direction.

If the friction ring 12 is compressed in the axial direction when inserted into an annular gap laterally bounded by two boundary surfaces, the preloading elements 17 exert an actuating force by which the friction members 14 are positioned with their lateral outer surfaces against the boundary surfaces laterally bounding the annular gap.

Show an alternative embodiment of a friction ring 12 Figure 7a and Figure 7b . On the friction ring 12 there are bending webs 18 which act in the axial direction and extend over at least a section of the circumference, which form the pretensioning elements and act as bending springs and exert an actuating force acting in the axial direction on side arms 19 which extend over a section of the circumference of the Friction rings extend in the circumferential direction. If the friction ring 12 is compressed in the axial direction when inserted into an annular gap laterally bounded by two boundary surfaces, the bending webs as pretensioning elements exert a restoring force through which the friction ring 12 with its outer surfaces formed by the side arms 19 is positioned against the boundary surfaces laterally bounding the annular gap will. This configuration also forms recesses 13 forming control edges 10.

In the two exemplary embodiments of a friction ring described above, it is ensured that the friction ring is received in the annular gap without play. In addition, the frictional torque that the friction ring experiences when it is held stationary in this with a rotating annular gap can be easily adjusted via the design of preloading elements, in the exemplary embodiments shown thus via the springs or the flexural webs and side arms. In the exemplary embodiment shown in the figures, the annular gap is formed between the inner ring of the bearing 31 and the lateral surfaces of the load toothing 5 ″ provided on the coupling member 2, facing it.

It should be noted that the arrangements or the assignments of the individual functional elements of the overrunning clutch, in particular the arrangement or assignment of the screw teeth, the control pawl, the control part, the control stops and the locking member with its locking elements on the first coupling member, the second Coupling member or the intermediate ring, as well as the questions as to which of the two coupling members is arranged in the overlap area on the inside or outside of the respective other coupling member, whether the outer or inner coupling member is rotationally driven or only has a support function and which of the toothing types is radially outside or radially are provided on the inside of the functional parts, for maintaining the basic function of the overrunning clutch described and for the structural design described as advantageous in the context of the invention are not mandatory and do not necessarily have to be provided as shown in the figures. By changing the arrangement or assignment of the individual functional elements compared to the configuration shown in the figures, the subject matter of the invention is not abandoned.

It should be pointed out again that the overrunning clutch, as shown in the figures, can be designed as a backstop. The overrunning clutch can, however, also be designed as an overrunning clutch in which one coupling part drives the other in a load transmission direction in rotation and is able to overtake in a freewheeling direction.

List of reference symbols

1

first coupling member

2

second coupling member

3

Intermediate link

4 '

external helical toothing on the intermediate link

4 "

internal helical teeth on the first coupling member

5 '

Internal teeth on the intermediate link

5 "

External teeth on the second coupling member

6th

Locking member (locking ring)

7th

Locking teeth

8th

Locking element actuators

9

Control element (control and synchronization latch)

10

Control edge

11th

Tax boom

12th

Control part (friction ring)

13th

Recesses in the friction ring

14th

Friction links

15th

Carrier ring

16 ', 16 "

Locking means

17th

Prestressing elements

18th

Bending web

19th

Side arms

30th

outer sealing cap

31

roller bearing

Claims (15)

1. Overrunning clutch having a first clutch member (1), a second clutch member (2) and an intermediate member (3) which interacts with the first clutch member (1) and second clutch member (2) and which, depending on the direction of the rotational loading of the overrunning clutch, can assume an overrunning position or an engagement position, wherein a change between the overrunning position and the engagement position occurs by an axial displacement of the intermediate member (3), and wherein at least one control mechanism is provided which initiates the axial displacement of the intermediate member (3) from the overrunning position into the engagement position by means of a control element (9), characterized in that the first clutch member (1) axially overlaps the second clutch member (2) in the engagement position with formation of an effective toothing width (B), and the control element (9) is arranged on the intermediate member (3) at least partially within the toothing width (B).
2. Overrunning clutch as claimed in claim 1 or as claimed in the preamble of claim 1, characterized in that the control element (9) is arranged on the intermediate member and, in the overrunning position, comes into contact with a load toothing provided on the first clutch member (1) or on the second clutch member (2) in order to initiate the axial displacement of the intermediate member into the engagement position (3) when the rotational loading changes from the overrunning rotation direction into the load rotation direction.
3. Overrunning clutch as claimed in claim 1 or claim 2, characterized in that a control part (12) which is arranged on the first clutch member (1) or on the second clutch member (2) and which interacts with the control element (9) in order to initiate the axial displacement of the intermediate member (3) is arranged radially on the inner side of the overlap.
4. Overrunning clutch as claimed in one of the preceding claims, characterized in that the intermediate member (3) is of annular design and has an outer annular surface provided at least partially with an outer load toothing (4') and has an inner annular surface provided at least partially with an inner load toothing (5'), wherein the outer load toothing (4') at least partially axially overlaps the inner load toothing (5').
5. Overrunning clutch as claimed in the preceding claim, characterized in that the outer annular surface is provided over the full axial width with the outer load toothing (4'), whereas the inner annular surface is provided only in a subportion with an inner load toothing (5').
6. Overrunning clutch as claimed in one of the preceding claims, characterized in that the intermediate member (3) has a helical toothing (5') on an inner annular surface or on an outer annular surface, wherein the helical toothing (5') on the intermediate member (3) is in engagement with a corresponding helical toothing (5") on one of the clutch members.
7. Overrunning clutch as claimed in one of the preceding claims, characterized in that the control mechanism is designed in such a way that it allows the axial displacement of the intermediate member (3) from the overrunning position into the engagement position only in defined angle-of-rotation positions ensuring the transfer of the intermediate member (3) into the engagement position.
8. Overrunning clutch as claimed in one of the preceding claims, characterized in that the control mechanism comprises a control part (12) which, depending on the direction of a relative rotation between the clutch members (1, 2), with the overrunning clutch loaded in the overrunning rotation direction F, continuously forces the control element (9) into the open position, wherein the control part (12) is in frictional contact with a clutch member (2) and, during a relative rotation of the clutch members (1, 2) with respect to one another, is positioned under frictional force loading directly or indirectly against the control element (9).
9. Overrunning clutch as claimed in claim 8, characterized in that the control part (12) is designed as a friction ring which is in frictional contact with a clutch member (2).
10. Overrunning clutch as claimed in one of the preceding claims, characterized in that one or more radial pocket-like depressions or apertures as control element receptacle(s) are incorporated in the intermediate member (3) for receiving the control element (9).
11. Overrunning clutch as claimed in one of the preceding claims, characterized in that a blocking member (6) is provided which blocks the axial displacement of the intermediate member (3) from the engagement position into the overrunning position when the blocking member (6) is situated in a blocking position, and releases the axial displacement of the intermediate member (3) from the engagement position into the overrunning position when it is situated in a release position.
12. Overrunning clutch as claimed in the preceding claim, characterized in that the blocking member (6) has a blocking toothing (7) which corresponds to a helical toothing (4") of a clutch member (1) or a blocking toothing (7) which corresponds to the load toothing (5") of a clutch member (2) and which, with the blocking member (6) situated in the release position, overlaps with the helical toothing (4") or load toothing (5") which is provided on the respective clutch member and which corresponds to the blocking toothing (7), with the result that the intermediate member (3) can move axially into the blocking member (6) to assume the overrunning position.
13. Overrunning clutch as claimed in one of the three preceding claims, characterized in that the blocking member (6) is designed as an externally switchable blocking member which is transferred by an external actuation from the blocking position into the release position and/or from the release position into the blocking position, wherein the blocking member (6) is of monostable design and either the blocking position or the release position forms a base position which the blocking member (6) automatically assumes when it is not forceloaded by the actuator.
14. Electric motor driven axle drive unit having a 2-speed planetary gear mechanism via which various transmission stages are realized between an electromotive drive motor and the drive wheels driven by the axle drive unit, wherein by the use of an overrunning clutch as claimed in one of the preceding claims in the axle drive unit the overrunning clutch is used to realize the transmission stage of the 2-speed planetary gear mechanism by blocking or releasing the rotation of a sun wheel and/or a planet set and/or an annulus.
15. Electric motor driven axle drive unit as claimed in the preceding claim, characterized in the overrunning clutch is an overrunning clutch which can be blocked by means of a blocking member (6) and which is used as a backstop, and a reverse gear and/or recuperation operation is made possible via the overrunning clutch by means of the blocking member.

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